feat($compile): simplify isolate scope bindings

Changed the isolate scope binding options to:
  - @attr - attribute binding (including interpolation)
  - =model - by-directional model binding
  - &expr - expression execution binding

This change simplifies the terminology as well as
number of choices available to the developer. It
also supports local name aliasing from the parent.

BREAKING CHANGE: isolate scope bindings definition has changed and
the inject option for the directive controller injection was removed.

To migrate the code follow the example below:

Before:

scope: {
  myAttr: 'attribute',
  myBind: 'bind',
  myExpression: 'expression',
  myEval: 'evaluate',
  myAccessor: 'accessor'
}

After:

scope: {
  myAttr: '@',
  myBind: '@',
  myExpression: '&',
  // myEval - usually not useful, but in cases where the expression is assignable, you can use '='
  myAccessor: '=' // in directive's template change myAccessor() to myAccessor
}

The removed `inject` wasn't generaly useful for directives so there should be no code using it.

1 files changed, 12 insertions, 9 deletions

diff --git a/src/ng/directive/input.js b/src/ng/directive/input.js
index aa79082b..04af4c2a 100644
--- a/src/ng/directive/input.js
+++ b/src/ng/directive/input.js
@@ -857,8 +857,8 @@ var VALID_CLASS = 'ng-valid',
  * </example>
  *
  */
-var NgModelController = ['$scope', '$exceptionHandler', '$attrs', 'ngModel', '$element',
-    function($scope, $exceptionHandler, $attr, ngModel, $element) {
+var NgModelController = ['$scope', '$exceptionHandler', '$attrs', '$element', '$parse',
+    function($scope, $exceptionHandler, $attr, $element, $parse) {
   this.$viewValue = Number.NaN;
   this.$modelValue = Number.NaN;
   this.$parsers = [];
@@ -870,6 +870,14 @@ var NgModelController = ['$scope', '$exceptionHandler', '$attrs', 'ngModel', '$e
   this.$invalid = false;
   this.$name = $attr.name;
 
+  var ngModelGet = $parse($attr.ngModel),
+      ngModelSet = ngModelGet.assign;
+
+  if (!ngModelSet) {
+    throw Error(NON_ASSIGNABLE_MODEL_EXPRESSION + $attr.ngModel +
+        ' (' + startingTag($element) + ')');
+  }
+
   /**
    * @ngdoc function
    * @name angular.module.ng.$compileProvider.directive.ngModel.NgModelController#$render
@@ -974,7 +982,7 @@ var NgModelController = ['$scope', '$exceptionHandler', '$attrs', 'ngModel', '$e
 
     if (this.$modelValue !== value) {
       this.$modelValue = value;
-      ngModel(value);
+      ngModelSet($scope, value);
       forEach(this.$viewChangeListeners, function(listener) {
         try {
           listener();
@@ -987,9 +995,7 @@ var NgModelController = ['$scope', '$exceptionHandler', '$attrs', 'ngModel', '$e
 
   // model -> value
   var ctrl = this;
-  $scope.$watch(function() {
-    return ngModel();
-  }, function(value) {
+  $scope.$watch(ngModelGet, function(value) {
 
     // ignore change from view
     if (ctrl.$modelValue === value) return;
@@ -1044,9 +1050,6 @@ var NgModelController = ['$scope', '$exceptionHandler', '$attrs', 'ngModel', '$e
  */
 var ngModelDirective = function() {
   return {
-    inject: {
-      ngModel: 'accessor'
-    },
     require: ['ngModel', '^?form'],
     controller: NgModelController,
     link: function(scope, element, attr, ctrls) {